Looking at Buildings

Materials & Construction


Metals which occur naturally in the rock formations of England need to be extracted and smelted to create a material which can be worked into a variety of forms. The principal ores which have been used in English building are lead, copper, and iron. Although copper and lead had a practical application of providing roof coverings, only iron has played a major role in the developement of building technology, not least as the basis for the production of steel. Iron ore was mined and smelted with charcoal, requring a good source of woodland closeGlossary Term to the mines. However timber was becoming increasingly restricted by the end of the 18th century and from that date coke and coal were employed in the smelting process, causing the industry to be concentrated in the areas where these materials were available. Once smelted the iron needed to be hammered, while hot, into its final shape. The size of the finished article was therefore limited both by the amount of smelted ore available and the speed with which the smith could achieve his work. Most wrought ironGlossary Term components were therefore modest in size e.g. nails or hinges but once hardened the material was extremely durable.

Although almost all iron had to be wrought by hand, it was also possible to cast the smelted ore into shapes by using moulds. This method offered the possibility of mass production for decorative and other components and eventually entirely superseded small-scale wrought ironGlossary Term production. Cast ironGlossary Term revolutionised building technology from the end of the 18th century, when it was first used in a structural capacity. Its strength made it suitable for load-bearing but its brittle nature meant it was liable to fracture under tension.

Large scale production of wrought ironGlossary Term for structural use was aided by Henry Cort's development of the puddling process in 1784 and the subsequent invention of mills for rolling the iron into bars and other standard components suitable for building. Its flexibility and strength under tension made it suitable for trusses and beams and in particular for wide-span structures such as bridges.

The major innovation in the structural use of metals was the discovery of steel. After c.1880 rolled steel, similar but stronger than wrought ironGlossary Term was used in creating self-supporting framed structures which could be built to great heights.

Since the mid-20th century numerous other metals, such as aluminium, have also played an increasing role in different types of structure.


Cast iron

Hard and brittle iron, cast in a mould to the required shape rather than forged. Compare wrought iron.


The precinct of a cathedral. Also (Scots) a courtyard or passage giving access to a number of buildings.

Wrought iron

Ductile iron that is strong in tension, forged into decorative patterns or forged and rolled into e.g. bars, joists, boiler plates. Compare cast iron.